Environmentally improved rearview mirror assembly

ABSTRACT

An environmentally improved rearview mirror assembly is provided which incorporates a reflective element with variable reflectance. In one embodiment, the environmentally improved rearview mirror assembly is substantially free of cadmium (Cd). In another embodiment, the environmentally improved rearview mirror assembly is substantially free of lead (Pb). In yet another embodiment, the environmentally improved rearview mirror assembly is substantially free of mercury (Hg). In a further embodiment, the environmentally improved rearview mirror assembly is substantially free of poly-vinyl-chloride (PVC). In yet a further embodiment, the environmentally improved rearview mirror assembly is substantially free of halogen producing chemicals such as bromine (Br).

BACKGROUND OF THE INVENTION

[0001] Rearview mirrors have long been incorporated into vehicles forproviding the controlled vehicle operator with a generally rearward viewof the controlled vehicle while the operator's vision is generallydirected toward the front windshield of the controlled vehicle. Rearviewmirrors are often times mounted inside and outside the vehicle.Typically, one rearview mirror is mounted in the upper, center, area ofthe front windshield inside the vehicle. A second rearview mirror istypically mounted in the lower, forward, area of the driver's sidewindow outside the vehicle. It is common to have a third rearview mirrormounted in the lower, forward, area of the passenger side window, alsooutside the vehicle.

[0002] Recently, variable reflectance, reflective elements have beenincorporated into both the inside and, more recently, into the outsiderearview mirrors of vehicles. Variable reflectance mirrors sense ambientand, or, glare light levels and automatically vary the reflectance ofthe given reflective element to prevent the eyes of the operator of thecontrolled vehicle from being subjected to high levels of reflectedlight. The headlights of trailing vehicles and the sun, while near thehorizon behind the controlled vehicle, are two common sources of “glare”light. One inherent benefit of variable reflectance rearview mirrors,related to nighttime driving, is that headlights of trailing vehiclesare sensed by the associated automatic mirror control and thereflectance is automatically adjusted to minimize the glare imposed uponthe eyes of the operator of the controlled vehicle while maximizing rearvision.

[0003] Devices of reversibly variable transmittance to electromagneticradiation, wherein the transmittance is altered by electrochromic means,are described, for example, by Chang, “Electrochromic andElectrochemichromic Materials and Phenomena,” in Non-emissiveElectrooptic Displays, A. Kmetz and K. von Willisen, eds. Plenum Press,New York, N.Y. 1976, pp. 155-196 (1976) and in various parts ofEletrochromism, P. M. S. Monk, R. J. Mortimer, D. R. Rosseinsky, VCHPublishers, Inc., New York, N.Y. (1995). Numerous electrochromic devicesare known in the art. See, e.g., Manos, U.S. Pat. No. 3,451,741;Bredfeldt et al., U.S. Pat. No. 4,090,358; Clecak et al., U.S. Pat. No.4,139,276; Kissa et al., U.S. Pat. No. 3,453,038; Rogers, U.S. Pat. Nos.3,652,149, 3,774,988 and 3,873,185; and Jones et al., U.S. Pat. Nos.3,282,157, 3,282,158, 3,282,160 and 3,283,656.

[0004] In addition to these devices there are commercially availableelectrochromic devices and associated circuitry, such as disclosed inU.S. Pat. No. 4,902,108, entitled “Single-Compartment, Self-Erasing,Solution-Phase Electrochromic Devices Solutions for Use Therein, andUses Thereof”, issued Feb. 20,1990 to H. J. Byker; Canadian Patent No.1,300,945, entitled “Automatic Rearview Mirror System for AutomotiveVehicles”, issued May 19, 1992 to J. H. Bechtel et al.; U.S. Pat. No.5,128,799, entitled “Variable Reflectance Motor Vehicle Mirror”, issuedJul. 7, 1992 to H. J. Byker; U.S. Pat. No. 5,202,787, entitled“Electro-Optic Device”, issued Apr. 13, 1993 to H. J. Byker et al.; U.S.Pat. No. 5,204,778, entitled “Control System For Automatic RearviewMirrors”, issued Apr. 20,1993 to J. H. Bechtel; U.S. Pat. No. 5,451,822,entitled “Electronic Control System”, issued Sep. 19,1995 to J. H.Bechtel et al. and U.S. Pat. No. 6,402,328, entitled “Automatic DimmingMirror using Semiconductor Light Sensor with Integral ChargeCollection,” issued Jul. 11, 2002 to Bechtel et al. Each of thesepatents is commonly assigned with the present invention and thedisclosures of each, including the references contained therein, arehereby incorporated herein in their entirety by reference. Suchelectrochromic devices may be utilized in a fully integratedinside/outside rearview mirror system or as separate inside or outsiderearview mirror systems.

[0005] With the increased numbers of variable reflectance mirrors beingused, there is a correspondingly increased desire to provide anenvironmentally improved variable reflectance mirror design. Millions ofmirrors are being produced annually that incorporate variablereflectance elements with the above mentioned components.

[0006] Known variable reflectance mirrors incorporate photo cells forsensing the ambient and glare light. Most commonly used photo cellscomprise a cadmium-based material as the active medium for sensingoptical radiation. The output of the photo cell is incorporated into anassociated automatic mirror control. It is common for variablereflectance mirrors to incorporate one photo cell for sensing ambientlight and a second cell for sensing glare light. Cadmium Sulfide (CdS)and Cadmium Telluride (CdTe) are two commonly used materials in photocells.

[0007] Additionally, it has been common practice to treat variouscomponents within mirrors with Cadmium to prevent corrosion.Particularly, with regard to mirrors installed outside the vehicle,corrosion prevention is preferred.

[0008] Typical control circuitry for use with a variable reflectancemirror element incorporates lead-based solder for interconnection of thevarious electrical components including connection of the photo cells.It is common to use a printed circuit board for mounting the individualelectrical components.

[0009] Bromine (Br) is commonly added to printed circuit boards in theform of tetrabromo-bisphenol A (TBBPA) as a flame-retardant. Wheninvolved in a fire, TBBPA produces toxic and corrosive gases such ashalide gases and halogen. Brominated epoxy resin exhibits high flameretardancy. However, it generates noxious hydrogen bromide, polybrominedibenzofurans, and polybromine dibenzodoxins when burned. Moreover,antimony trioxide (Sb₂O₃), a synergist commonly used in combination withbrominated epoxy resin has recently been labeled as a suspectedcarcinogen.

[0010] It is also common for the reflective elements in a mirror,variably reflective or not, to incorporate a lead-based paint on atleast one surface of the associated substrates. Use of a protective coatof lead-based paint enhances the long-term reflective clarity and thedurability of reflective elements. Typically, silver (Ag), or a silveralloy, is used as a reflective coating on a piece of glass to derive thereflective characteristic of a mirror. Without the lead-based paintcoating over the silver, oxidation will cause degradation of the silvercoating.

[0011] It is common for inside rearview mirrors to comprise switches andpush buttons for human interaction. The switches and push buttonsprovide a host of control features such as map lights, telematicfunctions, compass readings, temperature readings, etc. Mercury (Hg)containing switches are commonly used in electrical circuitry.

[0012] Typically, the reflective element and associated controlcircuitry, circuit boards and pushbutton switches are incorporated intoa mirror housing with a bezel defining an opening for viewing thereflective element. It is common for the housing and bezel to be moldedfrom a poly-vinyl-chloride (PVC) material.

[0013] Cadmium (Cd) is a known cancer-causing agent. Lead (Pb) is knownto produce undesirable effects in humans. Bromine (Br) containingprinted circuit boards are known to produce halide gasses, such ashalogen, during the manufacture of related electrical circuits and inthe event of circuit board fires. Mercury (Hg) has been well identifiedas an environmentally damaging material. Poly-vinyl-chloride is alsoknown to be harmful to the environment when discarded.

[0014] Many automotive manufactures, suppliers and consumers have becomemore environmentally conscious and responsible. Additionally, there aremore environmental regulations that require products to beenvironmentally improved. Therefore, there remains a need in the art ofvehicle rearview mirrors for a variable reflectance mirror assembly thatis environmentally improved.

SUMMARY OF THE INVENTION

[0015] A rearview mirror assembly with automatically variablereflectivity is provided that incorporates a cadmium (Cd) free photocell for sensing the ambient and, or, glare light. Relatively new typesof light sensors incorporate a silicon-based light transducer andassociated conditioning electronics on a single substrate. The abilityto incorporate additional electronics on the same substrate as the lighttransducer increases component integration. Component integrationadditionally reduces the system components that comprise environmentallyharmful materials. Types of charge accumulating light transducers foruse with the present invention include photodiodes and photogatetransistors. A variety of charge integrating photodiode devices havebeen described including those in U.S. Pat. No. 4,916,307 to Nishibe etal.; U.S. Pat. No. 5,214,274 to Yang; U.S. Pat. No. 5,243,215 to Enomotoet al.; U.S. Pat. No. 5,338,691 to Enomoto et al.; and U.S. Pat. No.5,789,737 to Street. Photogate transistor devices are described in U.S.Pat. No. 5,386,128 to Fossum et al.; U.S. Pat. No. 5,471,515 to Fossumet al. and U.S. Pat. No. 6,359,274, to Nixon et al. Each of thesepatents is herein incorporated in its entirety by reference.

[0016] A mirror assembly substantially free of Cadmium is provided byreplacing Cadmium-treated metallic components with metallic componentstreated with zink, phosphate, black oxide, or the like, in addition toemploying Cadmium free photo cells.

[0017] In another embodiment of the present invention, a reflectiveelement substantially free of lead-base paint is provided. Many knownrearview mirrors incorporate a lead-based paint as a protective coatingfor, otherwise, exposed surfaces. U.S. Pat. No. 5,818,625, to Forgetteet al., describes an electrochromic rearview mirror incorporating athird surface metal reflector for use with the present invention. Thelead-based paint protective coat of the prior art mirror is deleted inthe reflector of the '625 patent. The disclosure of the '625 patent isincorporated herein by reference thereto.

[0018] In another embodiment of the present invention, an electricalcontrol circuit is provided that is substantially free of lead-basedsolder. Lead-free solder joining for electrical componentinterconnection and for attaching electrical components to printedcircuit boards has been gaining in popularity. Until recently, the glasstransition temperature (Tg) of known lead-free solder was too high forreliably joining electrical components that are heat sensitive. Theassociated soldering processes caused damage to the associatedelectrical components. Silicon-based light sensors used in variousembodiments of variably reflective mirrors in accordance with thepresent invention are particularly susceptible to damage when exposed tohigh temperatures. Recently, more acceptable lead-free solders andassociated soldering processes have been developed for use with thepresent invention. Tin (Sn), zinc (Zn), silver (Ag) and copper (Cu)alloys are known substitutes for lead (Pb) and lead alloys.

[0019] In another embodiment of the present invention, a rearview mirrorassembly is provided substantially free of bromine(Br) and halide gasproducing materials. Printed circuit boards are now available thatcomprise non-halogen producing and non-phosphorus flame retardantmaterials. One such printed circuit board material for use with thepresent invention is described in U.S. Pat. No. 6,337,363, to Lee et al.The disclosure of the '363 patent is incorporated herein in its entiretyby reference.

[0020] In another embodiment of the present invention, a rearview mirrorassembly is provided that is substantially free of poly-vinyl-chloride(PVC). Many alternatives to poly-vinyl-chloride (PVC) containingmaterials have been developed for molding mirror housings and bezels. Inone embodiment of the present invention, a housing and bezel areprovided free of PVC. Acrylonitrile-Butadiene-Styrene-Poly-Carbenate(ABSPC) and Acrylonitrile-Styrene-Acrylate (ASA) are two knownreplacements for PVC. Magnesium alloy is another material for use withrearview mirror assemblies in accordance with this embodiment of thepresent invention. Other PVC free materials may be used in accordancewith this embodiment of the present invention.

[0021] The features and advantages of the present invention will becomereadily apparent from the following detailed description of the bestmode for carrying out the invention when taken in connection with theaccompanying figures and appended claims.

BRIEF DESCRIPTION OF THE FIGURES

[0022]FIG. 1 depicts a reflective element of a non-variable reflectancemirror;

[0023]FIG. 2 depicts a perspective view of a mirror incorporating avariable reflectance element in accordance with the present invention;and

[0024]FIG. 3 depicts an exploded view of the mirror of FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] The environmentally improved rearview mirror assemblies inaccordance with the present invention anticipate the need to discard theassembly once the vehicle that incorporates the assembly reaches the endof its useful life. Rearview mirror assemblies in accordance withvarious embodiments of the present invention incorporate components thatare environmentally friendly.

[0026] Turning to FIG. 1, a reflective element 5 is shown to include apiece of glass 11 with a first surface 10 and a second surface 12. It iscommon for such reflective elements to incorporate a reflective coating15, such as silver (Ag), on the second surface of the glass 11. As iswell known, silver exposed to air becomes oxidized over time and turns ayellowish-brown; oxidation is particularly problematic in warm, humid,environments. This oxidation negatively affects the reflectivity andclarity of that associated mirror.

[0027] In an effort to overcome the oxidation problem, it has becomecommon to coat the silver or silver alloy coating with a layer oflead-based paint 20. The coating of lead-based paint 20 seals the silverfrom the surrounding air, thereby, impeding oxidation of the silver.

[0028] It is commonly accepted that lead (Pb) in lead-based paint isharmful to the environment when the associated mirror assembly isdiscarded. The negative effects of lead (Pb) when ingested by humans arewell known. Many alternatives to lead-based paints have been developedand are preferred for use with the present invention. One embodiment ofthe present invention, as described herein, obviates the need for anoxidation inhibiting material entirely.

[0029] Turning now to FIGS. 2 and 3, a rearview mirror assembly 100 isshown to include a variable reflectance element 105. Although only aninside rearview mirror is shown, the embodiments of the presentinvention described herein are equally applicable to outside rearviewmirrors. Variable reflectance elements 105 have recently been gaining inpopularity for vehicle applications. One such variable reflectanceelement for use within the present invention is described in U.S. Pat.No. 5,818,625, to Forgette et al., which is of common assignment withthe present application. The disclosure of the '625 patent isincorporated in its entirety herein by reference. As described in the'625 patent, the lead-based paint is deleted. As shown in FIG. 3, and asdescribed in detail in the disclosure of the '625 patent, the preferredvariable reflectance element 105 incorporates a first piece of glass 110and a second piece of glass 111. The first piece of glass 110 comprisesa first surface 106 and a second surface 107. The second piece of glass111 incorporates a third surface 108 and a fourth surface 109. It hasbecome common in the art of variable reflectance mirror elements torefer to the four surfaces as labeled herein.

[0030] As described in the '625 patent, a reflective layer 115, such assilver (Ag), chromium (Cr), rhodium (Rh), ruthenium (Ru), etc. or ametallic alloy, is applied to the third surface 108. A variablytransmissive medium 112, along with the reflective layer 115 issandwiched between the second surface 107 and the third surface 108. Aseal (not shown) is place between the second and third surfaces, nearthe perimeter of the pieces of glass 110,111 such that the reflectivelayer 115 and variably transmissive medium 112 are isolated from thesurrounding air. Preferably, the variably transmissive medium 112 is anelectrochromic medium as described in the '625 patent.

[0031] By placing the reflective layer 115 on the third surface 108 andsealing off the surrounding air, the lead-based paint coating is nolonger needed to prevent oxidation of the reflective layer. Thus, therearview mirror assembly in accordance with one embodiment of thepresent invention is substantially free of lead-based paint. It is alsoin accordance with the present invention to use a non-variablereflectance element free of lead base paint. U.S. Pat. No. 6,147,803, toLaroche et al., that is incorporated in its entirety herein byreference, discloses a substitute for lead-based paint. This lead-freepaint system can be used on variably-reflective andnon-variably-reflective mirror assemblies in accordance with variousembodiments of the present invention.

[0032] It has become common for variable reflectance elements 105 to becombined with associated electrical circuits 140 to provideautomatically variable reflectance rearview mirrors. It has also becomecommon to incorporate a glare sensor 125 a for sensing light rays thatare directed toward the associated variable reflectance element 105.Additionally, it has become common to incorporate an ambient sensor 125b for sensing the ambient light rays surrounding the associated mirrorassembly. Cadmium (Cd) containing photo cells have been commonly usedfor light sensors in known variable reflectance rearview mirrorassemblies.

[0033] Most recently, cadmium containing photo cells are being replacedwith silicon based lights sensors. U.S. Pat. No. 6,359,274, to Nixon etal., which is incorporated in its entirety herein by reference,discloses a rearview mirror assembly incorporating an silicon-basedlight sensor. Silicon is environmentally preferred with respect tocadmium. Additionally, use of a silicon-based sensor facilitatesintegration of additional electrical components, such as transistors andoperational amplifiers, onto a common silicon substrate. Integration ofelectrical components further improves the environmental aspects ofvarious embodiments of the present invention.

[0034] Other types of charge accumulating light transducers that may beused with various embodiments of the present invention includephotodiodes and photogates. A variety of charge integrating photodiodedevices exist, including those in U.S. Pat. No. 4,916,307 to Nishibe etal.; U.S. Pat. No. 5,214,274 to Yang; U.S. Pat. No. 5,243,215 to Enomotoet al.; U.S. Pat. No. 5,338,691 to Enomoto et al.; and U.S. Pat. No.5,789,737 to Street. Photogate transistor devices are described in U.S.Pat. No. 5,386,128 to Fossum et al. and U.S. Pat. No. 5,471,515 toFossum et al. Each of these patents is herein incorporated in itsentirety by reference.

[0035] Cadmium causes other problems in rearview mirror assemblies, inthat it has been common to provide metallic components and fastenersthat incorporate a cadmium treatment for corrosion prevention. Cadmiumtreatment is commonly used on the windshield attachment shoe for themirror assembly mount, the mirror assembly mount, fasteners to connectthe mount to the mirror assembly housing, fasteners used to mountcomponents within the housing, and screws used to attach various mirrorassembly components to one another, as well as, miscellaneous connectorswithin the rearview mirror assemblies. In an effort to improve theenvironmental properties of the rearview mirror assembly, othermaterials may be used. In at least one embodiment of the presentinvention, the rearview mirror assembly may employ metallic componentsand fasteners treated with zink, phosphate, black oxide or similarcorrosion prevention materials in lieu of cadmium treated metalliccomponents and fasteners.

[0036] Thereby, the preferred rearview mirror assembly in accordancewith one embodiment of the present invention is substantially free ofcadmium (Cd). It is within the scope of the present invention to use anycadmium free photo cells and cadmium free corrosion treatment.

[0037] It is common for electrical circuits within variable reflectancerearview mirrors to incorporate lead-based solder for interconnectingthe associated individual components, as well as, for connecting theambient and glare sensors. In a preferred embodiment of the presentinvention, a non-lead-based solder is used for interconnection of theelectrical components. Solder connections include resistors,transistors, integrated circuit chips, printed circuit boards,electrical connectors, wire bonds, capacitors, inductors, electricalsockets, illuminators, pushbuttons, etc. generally shown as reference140 in FIG. 3. As mentioned above, recent developments in solderingprocesses, as well as, in the related materials has made it possible tointerconnect electrical components with lead-free solder. Additionally,the components listed above have become available free of lead coatingon the associated connectors and conductors.

[0038] Lead-free solder joining for electrical component interconnectionand for attaching electrical components to printed circuit boards hasbeen gaining in popularity. Until recently, the glass transitiontemperature (Tg) of known lead-free solder was too high for reliablyjoining electrical components that are heat sensitive. The associatedlead-free solder soldering processes caused damage to the associatedelectrical components. Recently, more acceptable lead-free solders andassociated soldering processes have been developed for use with thepresent invention. Tin (Sn), zinc (Zn), silver (Ag) and copper (Cu)alloys are being substituted for lead (Pb) and lead alloys and are inaccordance with the present invention. U.S. Pat. No. 6,241,145, to Maedaet al., which is incorporated herein by reference thereto, discloses alead-free solder joining method for use with the present invention.Thereby, the preferred rearview mirror assembly in accordance with oneembodiment of the present invention is substantially free of lead-basedsolder.

[0039] By utilizing a variable reflectance element, or a non-variablereflectance element, similar to those described above, substantiallyfree of lead-based paint in combination with a lead-free solder in theassociated rearview mirror assembly, a rearview mirror assembly inaccordance with one embodiment of the present invention is substantiallyfree of lead (Pb).

[0040] It has become generally common for electrical circuits toincorporated printed circuit boards for mounting and interconnectingindividual electrical components, this is equally true with regard toelectrical circuits of rearview mirror assemblies. The preferredelectrical circuits 140 in accordance with the present inventionincorporate printed circuit boards 141 free of bromine (Br) and otherhalogen producing materials. Bromine (Br) is commonly added to printedcircuit boards in the form of tetrabromo-bisphenol A (TBBPA) as aneffective flame-retardant. If involved in a fire, TBBPA produces toxicand corrosive gases such as halogen. Brominated epoxy resin exhibitshigh flame retardancy. However, it generates noxious hydrogen bromide,polybromine dibenzofurans, and polybromine diebenzodoxins when burned.Moreover, antimony trioxide (Sb₂O₃), a synergist commonly used incompany with brominated epoxy resin has recently been labeled as asuspected carcinogen.

[0041] U.S. Pat. No. 6,337,363, to Lee et al., which is incorporatedherein by reference thereto describes an epoxy resin composition withnon-halogen, non-phosphorus flame retardant for manufacturing printedcircuit boards 141. It is preferred to use a printed circuit board 141incorporating an epoxy similar to that described in the '363 patent.Thereby, a rearview mirror assembly 100 in accordance with oneembodiment of the present invention is substantially free of bromine(Br) and other halogen producing materials.

[0042] It is common for inside rearview mirrors to comprise switches andpush buttons for human interaction. The switches and push buttonsprovide a host of control features such as map lights, telematicfunctions, compass readings, temperature readings, etc. Mercury (Hg)containing switches are commonly used in electrical circuitry. Mercury(Hg) has been used as a medium in electrical devices to provide longlasting, highly conductive, switching. Switches and pushbuttons havebeen developed that have contacts incorporating materials such as gold(Au) to provide a long life, highly conductive, device. Thus, mercury(Hg) is no longer required to obtain a satisfactory device.

[0043] It is preferred to use pushbutton switches 130 in the rearviewmirror assembly in accordance with one embodiment of the presentinvention free of mercury (Hg). Thereby, the preferred review mirrorassembly 100 in accordance with the present invention is substantiallyfree of mercury (Hg).

[0044] As shown in FIG. 3, the individual components of the rearviewmirror assembly are contained within a housing 150 and associated bezel145. In a most preferred embodiment of the rearview mirror assembly 100in accordance with the present invention, the bezel 145 and housing 150are manufactured from a plastic material other than apoly-vinyl-chloride (PVC) material. Many such materials are known suchas Acrylonitrile-Butadiene-Styrene-Poly-Carbenate (ABSPC) andAcrylonitrile-Styrene-Acrylate (ASA). Thereby, the preferred rearviewmirror assembly 100 in accordance with the one embodiment of the presentinvention is substantially free of PVC material.

The invention claimed is:
 1. An environmentally improved rearview mirrorassembly, comprising: an electrical control circuit with at least onelight transducer; a variable reflectance reflective element; and atleast one metallic component, wherein the assembly is substantially freeof cadmium.
 2. An environmentally improved rearview mirror assembly asin claim 1, comprising a silicon-based light transducer.
 3. Anenvironmentally improved rearview mirror assembly as in claim 2, whereinsaid light transducer is a photodiode.
 4. An environmentally improvedrearview mirror assembly as in claim 2, wherein said light transducer isa photogate.
 5. An environmentally improved rearview mirror assembly asin claim 1, comprising at least one metallic component treated with amaterial selected from the group consisting of zink, phosphate, andblack oxide.
 6. An environmentally improved rearview mirror assembly asin claim 1, further comprising a reflective element substantially freeof lead-based paint.
 7. An environmentally improved rearview mirrorassembly as in claim 1, further comprising an electrical control circuitsubstantially free of lead-based solder.
 8. An environmentally improvedrearview mirror assembly as in claim 1, further comprising an electricalcontrol circuit substantially free of bromine.
 9. An environmentallyimproved rearview mirror assembly as in claim 1, further comprising anelectrical control circuit substantially free of mercury.
 10. Anenvironmentally improved rearview mirror assembly as in claim 1, furthercomprising a housing and bezel substantially free ofpoly-vinyl-chloride.
 11. An environmentally improved rearview mirrorassembly, comprising: a reflective element, said reflective elementcomprising; at least one glass substrate with a coating containingsilver on at least one surface; wherein the assembly is substantiallyfree of lead-based paint.
 12. An environmentally improved rearviewmirror assembly as in claim 11, wherein said reflective element hasvariable reflectance.
 13. An environmentally improved rearview mirrorassembly as in claim 11, wherein said reflective element iseletrochromic.
 14. An environmentally improved rearview mirror assemblyas in claim 11, further comprising an electrical control circuitsubstantially free of lead-based solder.
 15. An environmentally improvedrearview mirror assembly as in claim 11, further comprising anelectrical control circuit substantially free of bromine.
 16. Anenvironmentally improved rearview mirror assembly as in claim 11,further comprising an electrical control circuit substantially free ofmercury.
 17. An environmentally improved rearview mirror assembly as inclaim 11, further comprising a housing and bezel substantially free ofpoly-vinyl-chloride.
 18. An environmentally improved rearview mirrorassembly, comprising: a variable reflectance reflective element; and anelectrical control circuit, wherein the assembly is substantially freeof lead-based solder.
 19. An environmentally improved rearview mirrorassembly as in claim 18, wherein said lead-based solder is selected fromthe group comprising tin-zinc alloy, tin-silver alloy, andtin-silver-copper alloy.
 20. An environmentally improved rearview mirrorassembly as in claim 18, further comprising an electrical controlcircuit substantially free of bromine.
 21. An environmentally improvedrearview mirror assembly as in claim 18, further comprising anelectrical control circuit substantially free of mercury.
 22. Anenvironmentally improved rearview mirror assembly as in claim 18,further comprising a housing and bezel substantially free ofpoly-vinyl-chloride.
 23. An environmentally improved rearview mirrorassembly, comprising: a variable reflectance reflective element; anelectrical control circuit; and a printed circuit board, wherein theassembly is substantially free of bromine.
 24. An environmentallyimproved rearview mirror assembly as in claim 23, comprising a printedcircuit board made of epoxy resin having a nitrogen-compound-based flameretardant.
 25. An environmentally improved rearview mirror assembly asin claim 23, comprising a printed circuit board made of epoxy resinhaving a phosphorus-compound-based flame retardant.
 26. Anenvironmentally improved rearview mirror assembly as in claim 23,further comprising an electrical control circuit substantially free ofmercury.
 27. An environmentally improved rearview mirror assembly as inclaim 23, further comprising a housing and bezel substantially free ofpoly-vinyl-chloride.
 28. An environmentally improved rearview mirrorassembly, comprising: a reflective element; a housing; and a bezel,wherein the assembly is substantially free of poly-vinyl-chloride. 29.An environmentally improved rearview mirror assembly as in claim 28,wherein at least one of the housing or bezel comprisesAcrylonitrile-Butadiene-Styrene-Poly-Carbenate (ABSPC).
 30. Anenvironmentally improved rearview mirror assembly as in claim 28,wherein at least one of the housing or bezel comprisesAcrylonitrile-Styrene-Acrylate (ASA).
 31. An environmentally improvedrearview mirror assembly as in claim 28, wherein at least one of thehousing or bezel comprises magnesium alloy.